Display unit



Aug. 23, 1966 M. M. LEVY ETAL DISPLAY UNIT 9 Sheets-Sheet 1 Filed June 5, 1963 INVENTORS mm Q/MM g 3, 1966 M. M. LEVY ETAL 3,267,595

DISPLAY UNIT 9 Sheets-Sheet 2 Filed June 5, 1963 DECODER SoLEMmD E.

( CODE 0 CHARACTER \NPUT READ wuzes 47 IN VENTORS SELECTOR name: 1:. m1! 1p 9. 1m

3, 1966 M. M. LEVY ETAL 3,267,595

DISPLAY UNIT Filed June 5, 1963 9 Sheets-Sheet 5 Fzg-fi.

INVENTORS MAURICE M. LEVY DAVID 5. HA!

Aug. 23, 1966 r M. M. LEVY ETAL DISPLAY UNIT 9 Sheets-Sheet 4 Filed June 5, 1963 5 F 0 t n e U h I Maur/ce M. Levy Dav/ 1 5. Ha

UMMWLA Aug. 23, 1966 M. M. LEVY ETAL 3,267,595

DISPLAY UNIT Filed June 5, 1963 9 Sheets-Sheet 5 Invemor-s Maurice, M. Levy Dan J S. Hay

B m, wmm fw Mtornep Aug. 23, 1966 M. M. LEVY ETAL DISPLAY UNIT 9 Sheets-Sheet 6 Filed June 5, 1963 a m 0 e v/ n T vhw u w n Hi I Q 5. WM HH Hv 2 MU v/ DD Aug. 23, 1966 V ETAL 3,267,595

DISPLAY UNIT Filed June 5, 1963 9 Sheets-Sheet 7 Invenfor-as Maurk'ca M. Lavy David 5. Hay

k n 77 M/u g- 23, 1965 M. M. LEVY ETAL 3,267,595

DISPLAY UNIT Filed June 5, 1963 9 Sheet-Sheet a /2// 15/ 8 hvenzwr's 2 3 Maurice Mr Levy F1 53.

DEM/(.0! S. [By 1Z2), [9M MJW Attorneys.

Aug. 23, 1966 M. M. LEVY ETAL DI SPLAY UNIT 9 Sheets-Sheet 9 Filed June 5, 1965 In veni'ors Maurice M. Levy Dan/ cl 5. HQ.

Attorneys United States Patent 3,267,595 DISPLAY UNIT Maurice M. Levy, 208 Clemow Ave., Ottawa, ()ntario, Canada, and David S. Hay, Ottawa, Ontario, Canada; said Hay assignor to said Levy Filed June 5, 1963, Ser. No. 285,643 20 Claims. (Cl. 40-48) This application is a continuation-in-part of SN. 153,- 116, filed November 17, 1961, and now abandoned.

This invention relates to an improved display unit, that is to say a mechanism for displaying lettering, numerals, diagrams or any other intelligence capable of being represented by a series of black or other coloured dots. In particular, the invention is concerned with the provision of such a display unit in which a succession of letters, numerals or other representations can be displayed for sufficient time to be read by a viewer and then be replaced by further intelligence. An example of such a display unit is the type employed to pass news bulletins or other information, such as stock market prices, in an endless, ever-changing succession across a display area. Display units of this type are equally applicable to the showing of advertising material, and indeed have an infinite variety of possible uses.

The principal object of the invention is to provide such a unit having advantages over prior systems in respect of simplicity and ease of operation and maintenance, with corresponding cheapness of manufacture and reliability.

In its broad scope the invention consists of adisplay unit comprising an interconnected row of multifaced elements each mounted for independent movement relative to the row between a plurality of stable positions in each of which a respective distinctive face of said element defines a display array with the displayed faces of the other elements, actuating and indexing means for initiating and positively smoothly completing movements of a said element from one said position towards another and for retaining said element in said other stable position, and

means for moving the row and the actuating means relav tive to each other to bring each element successively into cooperating relationship with the actuating means.

Various examples of manners in which the invention may be carried into practice are illustrated diagrammatically and by way of example only in the accompanying drawings:

In these drawings:

FIGURE 1 is a perspective View of a first form of display unit;

FIGURE 2 is an enlarged perspective view, partly exploded to show the construction of a portion of the unit of FIGURE 1;

FIGURE 3 is a fragmentary view showing the manner of operation of the movable elements of the unit of FIG- URES 1 and 2;

FIGURE 4 is a fragmentary perspective view of a reset mechanism;

FIGURE 5 is a perspective view illustrating an alternative form that the movable elements may take;

FIGURE 6 is a further perspective view illustrating an alternative method of indexing the movable elements;

FIGURE 7 is a further fragmentary perspective view illustrating an alternative method of actuating and indexing the movable elements;

FIGURE 8 illustrates a control circuit for the system of FIGURE 1;

FIGURE 9 is a perspective view of a three-faced movable element demonstrating its manner of operation;

FIGURE 10 is a plan view of FIGURE 9;

FIGURE 10:: is a modified version of FIGURE 9;

FIGURE 11 is a perspective view of a four-faced movable element;

3,73%7595 Patented August 23, 1965 FIGURE 12 is a perspective view of a modified form of two-faced movable element and its method of actuation;

FIGURE 13 is a plan view of a modified three-faced element;

FIGURE 14 shows a perspective view of a modified actuation station in a system employing a modified twofaced element;

FIGURES 15a to 15g are a series of operating sequence diagrams for the construction of FIGURE 14;

FIGURE 16 is a diagram demonstrating the manner of non-operation of the construction of FIGURE 14;

FIGURE 17 is an underside perspective view of a reset station in a system employing the element shown in FIG- URE 14;

FIGURE 18 shows a perspective view of another operating station employing a further modified two-faced element;

FIGURES 19a to l9e are a series of operating sequence diagrams for the construction of FIGURE 18;

FIGURES 20a and 20b are diagrams demonstrating the non-operation of the FIGURE 18 construction;

FIGURE 21 shows a perspective view of yet another form of operating station for acting on a further modified two-faced element;

FIGURE 22 demonstrates one manner of operation of the FIGURE 21 assembly;

FIGURE 23 demonstrates a second manner of operation of the FIGURE 21 assembly;

FIGURE 24 is a view of a modification of FIGURE 3;

FIGURE 25 shows a dual actuation station;

FIGURE 26 shows a perspective view of a display unit in which the rows of elements remain stationary and the actuating means are moved relatively thereto;

FIGURE 27 is a large scale view of a fragment of FIG- URE 26; and

FIGURE 28 illustrates a read out station.

Reference will first be made to the construction illustrated in FIGURES 1 to 4. FIGURE 1 shows the display unit as consisting of a belt 1 extending around rollers 2 and 3, one of which is driven by motor 9 so that the belt circulates continuously, in the usual manner of an endless belt. The belt 1 is made up of a large number of elements 4 (see especially FIGURE 2) arranged in rows and columns and joined together by links 5 and a series of parallel pivot pins 6 which interconnect the links 5 and pass down through holes in the elements 4 so that they are each independently movable by rotation about a pin 6. These elements 4 are generally fiat and have two opposite faces, one of which is differently coloured from the other.

For clarity in making up letters and numerals etc., the colouring is preferably restricted to a circular portion 4a of the otherwise rectangular face. If preferred, the entire surface of one face may be coloured, but restriction of the colouring to the circular portions 4a renders the characters built up by such circular portions more realistic than if they were :built up with small squares. Normally the faces will be distinguished from each other by being black and white, which for the purposes of the present description are considered as colours, but clearly any distinctive colouring or shading will acooinplish the same object.

Each of the movable elements 4 is provided with an upper actuating lug 7 projecting from one of its faces and a lower resetting lug 8 projecting from the opposite face. Immediately behind the display span of the belt 1, that is the span shown towards the front of FIGURE 1, there are a number of guide strips 15. Except for portions adjacent the actuating mechanism, which will shortly be described, each of these strips 15 presents a smooth fiat surface to the rear faces of a row of movable eleseamen ments 1 ensuring that they travel along the operative display span of the unit without turning about their pivot pins 6, which otherwise they are free to do.

Such cooperation between a typical movable element 4 and a strip is shown diagrammatically in FIGURE 3, which also shows the manner in which the movable elements are actuated by means of a solenoid in controlling a trigger 14. When the trigger 14 is extended by solenoid 13 to project into the path of travel of the upper lug 7 of the next movable element 4 to travel past the actuation area, the trigger 14- will check travel of the lug 7 resulting in a clockwise turning movement being exerted on the movable element concerned. The leading edge of such movable element will be swung in towards the guide strip 15 and will enter a recess 16 located in such strip adjacent the solenoid and trigger assembly. Continued movement of the element 4- with the body of the belt will cause it to be turned through a full 180 before it re-emerges from the recess 16 to continue to slide along the guide strip 35. The position of this movable element will thus have been reversed so that its face bearing a black dot will be exposed. A similar guide strip 15, solenoid l3 and trigger i4 is associated with each row of the belt it which may consist of as many rows as conditions require and permit, and may even merely have a single row when elementary intelligence such as Morse code is to be displayed.

Immediately the movable element 4 considered in FIGURE 3 has passed the actuation area, the next such element of the belt will be in position for actuation or non-actuation, depending upon the state of excitation of the solenoid 13. If the trigger 14 does not project, the element continues along its trip 15 unchanged. Control of the various solenoids 13 (one for each row) will be exercised from a control circuit 1 2 into which the intelligence to be displayed is fed. Such devices are known but, for the purposes of completeness of the present disclosure, one example of such a circuit is given in FIG- URE 8. Excitation of solenoids 13 is synchronised with movement of the belt 1 by means of gear connection 10.

As FIGURE 1 demonstrates, once a group of movable elements has been set to display a character, this character will travel slowly along the display span of the unit. As each movable element reaches the far end of such span, it will be reset by a fixed trigger 17 (FIG- URE 4) projecting from the underside of each guide strip 315 to engage the lug of every movable element 4 that was turned around at the beginning of the span.

A further recess 18, corresponding to the recess 16 in function, is associated with each reset trigger 17.

If preferred, the lugs 8 can be dispensed with and the lugs 7 which now project forwardly on actuated movable elements can be used for resetting. In this case the reset trigger will require to be placed in front of rather than behind the belt 1, which arrangement can conveniently he achieved at the rear of the unit adjacent the return span. Numerous possible resetting arrangements are obviously possible and the exact form adopted is unimportant to the invention. Indeed, as explained below, it is possible to eliminate resetting altogether by a modification to the actuating trigger arrangement.

The movable elements 4 illustrated in FIGURES 1 to 4 are hollow and require two stampings. A simplified element 20 is shown in FIGURE 5 made as a single stain-ping to form slots 21 to receive a hinge pin. The element 28 has its edges 22 curved to facilitate its movement into and out of the recesses 16 or 13. As before, a lug 7 is provided and one of the sides of each element 20 will be coloured differently from the other side, to permit intelligence to be displayed by virtue of the chosen arrangement of elements 2%) turned around.

As will be evident from the foregoing, the essential feature of the movable elements is that they should be capable of being indexed between two positions on cominland, and that they should have two stable positions to occupy, in each of which positions a respective distinctive face of each element defines a display array with the displayed faces of the other elements. In the construction so far described, retention in these stable positions is achieved by causing the members to slide in engagement with the guide strips 15, while indexing for the full 180 on actuation is insured by the recesses 16 and 18 in cooperation with the remainder of the guide strips.

FIGURE 6 shows an alternative manner of indexing between two stable positions 180 apart. In this construction the bottom of a movable element 23 is provided with a cam 24 the face of which engages a complementary cam 25 which is fixed in position on an appropriate link When the movable element 23 is actuated by engage ment between its lug 7 and trigger 14, a rising surface as on cam 24 rides up on a rising surface 27 of cam 25. Only a comparatively short arcuate movement is required to accomplish this action, after which the cams continue to rotate with gradually downwardly sloping surfaces 28 and 29 in engagement. By this means, it is only necessary for the trigger 14- to insure that the movable member 23 has its movement initiated and carried through for a small angle. Beyond such initial movement, the action of gravity and the shaping of earns 2 and 25 ensures a full 180 turn. In addition springs may be provided to assist gravity if required. With this arrangement, the guide strips 15 are unnecessary and may be dispensed with.

As will also be evident, mechanical actuation is not an essential aspect of the invention. Any actuating means that will achieve the desired, result is accordingly within the ambit of the invention. One such possibility is illustrated in FIGURE 7, which shows a movable element 39 similar to the movable elements 4 of FIGURESI to 4, except that the element 38 is provided with a small permanent magnet 31 for cooperation with an electromagnet 32 which replaces the trigger 14. Assuming that the rear end of the permanent magnet 31, that is the end nearer the electro-rnagnet, is a south pole and the forward end a north pole, energization of the e-lectro-magnet 32 to present a south pole to the movable element will cause the latter to rotate clockwise sufficiently to enter the recess :6 in the manner already described. This recess 16 combined with the guide strip 15 then ensures indexing for the full 180. Alternatively, any other suitable indexing method, such as that of FIGURE 6, may be employed.

A noteworthy aspect of the present invention is its simplicity. An endless stream of characters or other intelligence can be caused to travel along the display span of the belt 1 and yet only a single, simple actuator (for example the solenoid 13 or the electro-magnet 32) is required for each row of the unit. Such actuators are fixed to the unit and require no means for causing them to travel with the intelligence displayed. This facilitates their mounting and their connection to the control circuit 12. On the other hand, since it is relative movement between the row of movable elements and the actuator that is required, it is Within the invention that the row of movable elements remains still while the actuator is moved. Such an arrangement might have advantages under special conditions, but normally it will be preferred to retain the actuator or actuators stationary and form the row or rows of movable elements as an endless belt which can be continuously caused to travel past a fixed actuation area.

One form that the control circuit 12 may conveniently take is illustrated in FIGURE 8. The seven solenoids 13 are driven from a core matrix having seven rows, each connected to a respective solenoid l3, and five columns, since the largest character to be illustrated is assumed to require five columns of movable elements 4 to display it. The columns (read Wires 47) of the matrix 46 are pulsed from a column selector 4! which in turn is actuated by a position detector 42 which is driven from the motor 9 through gearing it), as already explained. The position detector 42 pulses the column selector 41 periodically in order to insure proper spacing between the characters displayed, and, when pulsed, the selector 41 in turn ener-.

gizes its five read wires 47 sequentially. In this way, each of the respective read wires 47 is energized as a column of elements 4 approaches the solenoids 13 for actuation, or non-actuation, as the case may be.

The matrix 40 also contains a series of drive wires, only one of which, drive wire 43, has been illustrated. There will be a drive wire threaded through the matrix for each letter, numeral or other character to be displayed. The drive wire 43 which has been illustrated is so threaded through the matrix as to represent the letter A. Each of the drive wires will be separately energized either from a key board 44, in which a unique key is pressed to correspond to each character, or from a coded character decoder 45 which is a known device for transferring a coded character input received in binary or other coded form into a unique signal on a selected output wire.

The matrix 40 is such that its horizontal sense wires 46 will be energized only when they are connected to a crossover point (matrix core) which is energized both by a drive wire and by a vertical read wire.

Assume that the key for the letter A is depressed, or that a similar output is emitted by the coded character decoder 45. The drive wire 43 will be energized. This sets up a magnetic field in the matrix cores threaded by this drive wire, the magnitude of the current being such that these cores are all set to a saturated condition that is maintained even after the drive current decays. The core will then be set to display the letter A. As the display belt 1 advances, a pulse is applied from the position detector 42 to the column selector 41. This column selector 41 begins by energizing the read wire 47 of the first column so that a read current is applied to the cores in this column. The sense windings are threaded through the individual rows of the matrix so that when the read current is applied, a sense current appears in each of the rows of the first column which have been preset by the drive wire. No output pulses appear in the sense windings which thread cores which have not been so set. In the example illustrated, the five lowermost sense wires 46 will be energized to actuate the five lowermost solenoids 13, while the two uppermost sense wires will remain unenergized. As the belt 1 advances, the column selector 41 applies currents sequentially to the other read wires to read out the intelligence imparted by the drive wire into the sense wires and hence to the solenoids 13. In this way the required letter is transferred to the display elements 4.

When the full letter has thus been displayed, the core matrix will be reset by a resetting pulse of opposite polarity to that applied to the drive wires. Such resetting pulse will be applied to all the cores by resetting windings (not shown), the energisaltion of which is controlled by the position detector 42. Other known matrix arrangements could alternatively be used.

As an alternative, useful particularly when intelligence is to be displayed repeatedly, the solenoids 13 can be connected directly to a paper tape reader of known type, such reader employing a paper tape on which the desired characters have been punched.

The foregoing description is based on the assumption that adequate display can be achieved with a simple twotone contrast and hence that a multi-faced element of two faces is sufiicient. It is, however, within the scope of the present invention to employ movable elements having three, four or even more faces, if a multicolour display is required. The movable elements would require a corresponding number of stable positions and means would be required for actuating and indexing them between such stable positions. Two actuators arranged one after the other would enable a choice between exposing any one of the three sides of a three-faced movable element; similarly, three actuators could control a four-faced element and so on. Clearly, when the number of faces exceeds four, the clarity of display begins to fall off, as the non-exposed faces will be visible to some extent. Probably, as a practical matter, four-faces will be the maximum usable, ex-

6 cept if special viewing conditions are set up in which the edges of the movable elements are hidden from view, as by strip members travelling with the belt while situated forwardly thereof and between the columns of movable elements.

An example of a method of actuating a three-faced movable element 50 is shown diagrammatically in FIG- URES 9 and 10. The element 50 has a first, norm-ally exposed face 51 and two other faces 52 and 53 that may be exposed as desired. This can be achieved by two solenoid operated triggers 54 and 55 cooperating with three pins 56, 57 and 58 projecting up from the top of the element 50 at positions slightly off-set from the centers of the sides concerned, as FIGURE 10 demonstrates. If triggers 54 and 55 are both withdrawn, no actuation takes place. If trigger 54 only projects (as in FIGURE 10), it will be struck by pin 58, with the result that the element 50 will be rotated clockwise by Suitable indexing means, for example similar to that of FIG- URE 6 but for 120 indexing, will be provided.

An alternative method of indexing is illustrated in FIG-' URE 10a. In this case slots are cut from the top corners of the element 50 to provide straight edges 59 for engagement by a guide strip 59'. This guide strip will be generally similar to the guide strip 15, except that, since the triggers 54, 55 will bear against the pins during operation for virtually a complete turn of 120, there will be no call for any parts analogous to the recesses 16. The triggers will actuate and almost if not completely index the element into its new position, the function of the guide strip then being restricted to retaining the member in such position. In this application the portion of the guide strip 59 in the vicinity of the triggers can conveniently be resilient or resiliently mounted to yield as the movable element turns.

When thus turned through 120, face 52 will be exposed, and the pins will have taken up positions similar to those they originally occupied, except that pin 56 will be where pin 58 was, and so on. With the second trigger 55 withdrawn, pin 56 will pas freely. Also pin 58 which now occupies the position shown for pin 57 in FIGURE 10, will pass clear of the end of trigger 54 by reason of the slight off-set of this pin position towards the exposed face of the element.

If it is desired, on the other hand, to expose face 53, then trigger 55 is also actuated to project into the path of pin 56 which is moved into position between the triggers by the first 120 rotation. Pin 56 striking trigger 55 causes a second 120 clockwise rotation to expose face 53.

It will be observed from FIGURE 9 that pin 58 is shorter than the other two pins. This has no efiect on actuation, because both triggers 54 and 55 are set low enough to intercept even the short pin. However, on resetting, the shortness of pin 58 is significant. Two fixed projecting triggers are provided for resetting. It is believed unnecessary to illustrate these separately, as they will appear the same as the triggers 54 and 55 in FIGURE 10, except that they both project at all times, and with the further exception that they are both slightly raised so that the short pin 58 will pass beneath them while the longer pins 56 and 57 will strike them.

If the movable element 50 is in the position shown in FIGURE 10, with face 51 exposed, no resetting is requrred. Pin 58 passes under the resetting triggers and pin 57 just misses them. If face 53 is exposed, a single turn of 120 is required to reset. Resetting is clockwise, as actuation. Pin 57 will strike the first resetting trigger to bring the element to the orientation shown and pin 58 will pass under the second resetting trigger. If face 52 is exposed, two 120 turns will be required, and this will be accomplished by pin 56 first striking the first trigger and then pin 57 striking the second trigger.

The exact positioning of pins 56 to 58 is not especially critical. The positioning shown in FIGURE 10 is advantageous, as ensuring that the triggers act on the pins for a comparatively long arc of turning of the member Stl in order to check any tendency for the member to turn back to its former position. If preferred, the Pins may be mounted at or near the apices of the triangle formed by the top of the member 50, or at some point along the lines joining such apices to the axis.

FIGURE 11 shows a four-faced element with faces 61 to 64, one short pin 65 and three long pins 66'to 68. This element will be actuated by three movable actuating triggers spaced apart along the direction of travel of the element and arranged low enough to be engaged by all four pins, and will be reset by three fixed projecting triggers similarly spaced apart in the direction of travel and elevated sufficiently to be missed by only the short pin. As this arrangement, and its operation through 90 turns, is exactly analogous to that of the three-faced element 50, no further illustration or explanation is considered necessary. The pins must be off-set from the corners so that whichever pin occupies the trailing corner at the rear of the element (the position of pin 68 in FIG- URE 11) will pass just clear of the end of a projecting trigger that will engage the leading rear pin (pin 65 in FIGURE 11). Again thi off-setting is analogous to that shown in FIGURES 9 and 10.

To this stage of the description, it has been assumed that each movable element is reset every time it reaches the end of the display span, so that the actuating members (triggers or magnets), which set up the display, are always presented with a succession of similarly oriented movable elements. It is within the present invention however to dispense with resetting by modifying the actuating mechanism.

Such an arrangement, as applied to a row of two-faced elements generally similar to those of FIGURES 1 to 3, is illustrated in FIGURE 12. The element 70 here shown has oppositely projecting lugs 71 and 72 arranged at different levels. If plain face 73 i exposed and is to remain exposed, the free end of trigger74 which pivots at 75 is held down by solenoid 76. Consequently lug 71 does not strike thetrigger and the element 70 is not reversed. Had it been reversed on its previous passage past the trigger, so that its coloured face was still exposed, and lug 72 projected to the rear, this lug would have struck the trigger, and reversal taken place. A similar effect can be achieved in the magnetic form of operation (FIGURE 7), by controlling the polarity of the actuating electro-magnet 32, in place of control of the level of a mechanical trigger.

If the coloured face had been desired, the trigger would have been brought to its upper position to be engaged by lug 71 or missed by lug 72, as the case may be. Lugs 71 and 72 thus represent respectively actuating or resetting lugs, depending upon which face is considered the normal face to be presented.

This feature of combining resetting with actuation is also applicable to elements of more than two faces. Taking the three-faced element 86, for example shown in FIGURE 13, this is provided with coded pins arranged differently in each corner. Of the three selected possible positions, pins 81 and 82 occupy the two outermost, pins 83 and 84 the two innermost, and pins 85 and 86 are spaced apart. The broken line circles represent positions not occupied by pins. Two sets of three triggers will be required. The sets will be spaced apart in the direction of travel (as triggers 54 and 55 of FIGURES 9 and 10) and each set will comprise three triggers formed as keys. One key will penmit passage of pins 81 and 82 while being struck by either of the other pin combinations, and similarly the other keys will pass one combination and block either of the other two. If the trigger keys corresponding to the code of pins 81, 82, are projected, the element 80 will pass unchanged if it is oriented as shown in FIG- URE 13. But, if one of the other faces is to the front, the other pin combinations will strike the keys, either once or twice, depending on whether one or two 120 turns are required. This arrangement thus accepts non-oriented, that is to say non-reset, elements for proper actuations.

This method of actuating non-ori=ented elements by means of triggers formed as keys is equally applicable to the two faced elements, as well as to those of more than three faces.

FIGURES 14 to 17 show a further system according to the invention. FIGURE 14 illustrates the actuation station and shows for simplicity only a single two-faced movable element 99, although it is to be understood, as before, that there will be a continuous row of such elements, and usually a number of such rows arrangedone above the other. A guide strip 91 is provided with a recess 92. The element 9% is formed with a pair of wed gelike front and rear portions 93 and 94 (see also FIGURE 17 which shows element in reversed position) and cam surfaces 95 and 96. An actuating trigger 97 is continuously urged by spring 98 into the projecting position shown and whether actuation takes place or not is determined by a control bar 99 which can slide in a support 14)!) under the action of a solenoid 101.

Actuation is illustrated in the diagram sequence of FIGURES 15a to 15g. Control bar 99 is first moved to the right as shown in FIGURE'lSb so that when cam surface 95 meets the projecting end of trigger 97 the element 90 is free to turn clockwise in the manner shown in FIGURE 150. It will be observed that cam surface 95 is of decreasing .radius anticlockwise around the element 90, which factor, together with the friction between surface 95 and trigger 97, and the force of spring 95, induces clockwise turning of the element 90.

It is also noteworthy in this form of the invention that the element 90 does not rely on the surfaces of the recess 92 to induce turning (see the space 102). However, once turning has been initiated. by trigger 97, the surfaces of the recess 92 will positively ensure its completion, should the cooperation between cam surface 95 and trigger 97 occasionally fail to complete the movement. In this connection it will be seen that recess surface 163 has been made with a sharp edge in order to minimise the chance of an edge-on collision between it and the leading edge of wedge portion 93 of the element 9%.

FIGURE t15d shows the rotation further advanced, and FIGURE 152 shows it nearly complete. At this point contact between cam surface 95 and trigger 97 is broken, and completion of the rotation is brought about by contact between a smoothly curved recess surface 184- and hat face 105 of the element 90. FIGURE 15g shows the turned element 90 continuing along the guide strip 91 to the display area;

When non-actuation is desired the control bar 99 is placed in its forward position (FIGURE 16) where it bears against face 105 of element 99 to prevent rotation of the latter, until the face 106 of wedge portion 93 encounters the guide surface 103 which continues to check rotation. Trigger 97 is forced aside and spring 98 is compressed.

The reset station for element 90 is shown in FIGURE 17 and comprises a projecting trigger 107 urged by a spring 108 into the path of travel of the lower cam surface 96 of the element 90. Rotation is brought about in essentially the same manner as demonstrated in FIGURES 15a to g. Should the element 90 not have been actuated and thus not require resetting, it will be in the reverse position from that shown in FIGURE 17. Flat face I06 will encounter the trigger 10 7 and there will be no force tending to turn the element anticlockwise (as seen in FIGURE 17). Seen from above the resetting rotation is clockwise, of course, a continuation of the actuation rotation.

FIGURES 18 to 20 show another construction for achieving a like operation. Here the element 116 has a cam surface 111 on its leading end to cooperate with a trigger 112 mounted outwardly of a guide strip 113 and urged by a spring 114 towards a recess 115 in such strip. The control member this time takes the form of a pivoted arm 116. FIGURE 19:: shows initial contact between cam surface 111 and trigger 112 to initiate turning (control arm 116 being withdrawn). Continued rotation is demonstrated by FIGURES 19b and 190 where trigger 112 rides on continuing cam surface 117. Completion of rotation is ensured by contact between recess surface 118 and cam surface 111 (FIGURE 19d) and is continued by contact between the face of guide strip 113 and face 119 of the element 114 Although the control arm 116 has been shown withdrawn in all these views for simplicity, it can be released at any time after rotation has exceeded about 90, on the assumption that this arm will normally be spring urged to its blocking position (FIGURE 20a). In this position it stands in the way of face 12! of element 110 by the time cam surface 111 reaches trigger 112, and the element 1110 continues on its way unturned, as FIGURE 20b demonstrates, spring 114 being compressed. Resetting of element 110 will take place analogously to the manner shown in FIGURE 17 by means of a trigger acting on a lower cam surface.

A system requiring no resetting is shown in FIGURES 21 to 23. These views show a movable element 121 formed with oppositely projecting lugs 122 and 123 formed at different "levels with slot-s 124 and 125 at corresponding levels. The actuating element is a fiat wide bar 126 movable up and down by suitable control means (not shown) so as to register in level with one or other of the lugs. Assume the element 121 to have its white face 127 facing outwards as in FIGURE 21 and the bar 126 to be placed at the level of rear lug 123. These parts come into contact with each other as shown in FIGURE 22, with the result that the element is rotated clockwise to present its black face 128. Completion of the rotation is ensured by Iguide surfaces 129 recessed at 130.

Had the black face 1123 originally faced outwards, as shown in FIGURE 23, the lug 122 which then projects rearwardly would then pass beneath the bar 126. No turning would be induced and indeed any turning would be positively precluded by cooperation between surface 127 and the bar 126. The black face thus remains facing outwards. Thus with the bar 126 in this position, an element 121 leaving the actuation station will present its black face, regardless of the condition of the element when approaching the actuation station. Consequently no resetting is required.

If the bar 126 is moved down to the level of the lug 122, the effect will be always to finish showing the white face 127, regardless of which of the faces is outwards as the element approaches the actuation station.

The feature that undesired turning is positively prevented may be realised in ways other than those shown in the embodiments of FIGURES 14 to 23. An example is illustrated in FIGURE 24 which shows a view of a modified version of the arrangement shown in FIG- URE 3. To ensure that the element 4 does not turn clockwise even a small amount accidentally, when the trigger 14 is withdrawn, and hence either jam against the edge of the recess 16 or make a complete turn, a wire spring 137 is provided, anchored at 133, to bear lightly against the outer face of element 4 and exert a force tending to urge the rear of the element 4 against the guide strip 15 when the front of such element projects across the mouth of the recess 16. When trigger 14 is extended the force of spring 137 is easily overcome and the element 4 makes a 180 clockwise turn in the manner already described.

For high speed operation it may sometimes be convenient to employ a double actuation station, each section of which acts on each alternate movable element. FIGURE 25 demonstrates this diagrammatically with two different. types of elements 149 and 141 which are similar to the element 121 of FIGURES 21 to 23 except that the levels of the lugs and their corresponding slots are varied. The lugs 142, 143 of element define levels L1 and L2 into either of which a first actuating bar 144 can be moved. Likewise lugs 145, 146 of element 141 define levels L3 and L4 into either of which a second actuating bar 147 can be moved. The four levels are separate and distinct so that there can be no interference between bar 144 and the lugs of element 141 or between bar 147 and the lugs of element 140. On the other hand bar 144 positively prevents element 141 from turning as it bridges the recess 148 in guide strip 149, and similarly bar 147 positively prevents element 140 from turning as it bridges the recess 151. An element can only turn when one of its lug and slot combinations corresponds in level to an actuating bar, since the bars move up and down and always project into nearly touching contact with the fiat faces of the elements.

In this way two elements can be set simultaneously, so that each actuating bar has more time to take up a new position between the times while it is acting on those successive elements with which it coacts (every alternate element in the row).

FIGURE 26 shows a construction employing a fixed belt of rows and columns of elements 161 each independently pivotable about a vertical pin 162 (FIG- URE 27). A number of actuating means 163 equal to the number of rows of elements 161 is mounted on a carriage 164 having wheels 165 for travel in rails 166. Movement of the carriage 164 back and forth along the back of the belt 169 is controlled by a motor 167 acting through a chain 168.

Each actuating means 163 comprises a guide strip 169 formed with a recess 170, an actuating arm 171 and a rotary solenoid 172. The arm 171 is movable between its full and broken line positions by the solenoid 172, being biased to the broken line position by a spring 173. A soft spring strip 174 inhibits accidental deflection of an element 161 into the recess 170, but can be pushed aside by an actuated element. The elements 161 each carry a pair of oppositely facing lugs 175 and 176 arranged at different levels to correspond to the two levels of the actuating arm 171. Thus, as in the previously described embodiments, automatic resetting is achieved. An effective continuation of the guide strip 169 is provided by a cable 177 which acts to prevent rotation from their allotted positions of the elements 161 displaced from the actuating means 163.

The embodiment of FIGURES 26 and 27 is useful particularly with large displays in which the mass of the belt 160 is large and would present problems if it were to be a moving belt.

The lugs 1'75, 176 provide another example of the combined actuating and resetting function that can be achieved with an actuating member movable selectively into the path of either lug. FIGURES 21 to 23 and 25 provided earlier examples. The principle is not limited to a two faced element, but may be applied to other multi-faced elements.

As an alternative to arranging lugs at different levels, lugs 175, 176 could be at the same level, provided that means were employed, such as photocell means for sensing the orientation of each element by the difference between the color or reflection of the faces of the element and for operating the actuating means accordingly.

It may be desired to read out the information stored in an array of movable elements set up in accordance with the present invention, for example so that such information can be transferred to another display unit without reference to the original source of information. The arrangement of FIGURE 28 can then be used. This figure shows a fragment of a movable belt of elements 4 (FIGURE 1) illustrating a pair of such elements at a read out station. A relay 180 is provided for each row and these relays are either closed by a lug 7 to sense an actuated element 4a or are left open to sense an unactuated element 4b. Other analogous sensing means can be used to detect other lug configurations or a magnetic polarity (when using elements such as the elements 30 of FIGURE 7). Alternatively, optical sensing means can be employed to project an image of the differently coloured faces of the display array onto a bank of photocells to provide similar read out signals. Such read out mechanisms are applicable equally to the systems in which the actuating means move (FIGURE 26), in which instance the read out station would similarly travel along the belt of display elements.

Reference has been made in this document to actuating means, to indexing means and to control means. In specific examples, various triggers and magnets have been referred to as constituting these means; and the guide strips (with or without recesses) and the cams often function as indexing means. In large measure the functions of these means overlap. Their combined function is actually threefold:

(a) to initiate turning of a movable element (more than once sometimes, in the case of movable elements have more than two sides) when the control circuit so demands,

(b) to ensure that turning of an initiated movable element is smoothly and positively completed through the full angle required, and

(c) to retain the movable element in the new position thus achieved during travel along the display span of the device. In addition, in some instances the actuating and/ or control means individually or together also serve (d) to block turning accidentally of a movable element that has deliberately not been actuated.

We claim:

1. A display unit comprising a row of multi-faced elements each mounted for independent display changing movement relative to the row between a plurality of stable positions in each of which a respective distinctive face of said element defines a display array with the display faces of the other elements, actuating and indexing means for initiating and completing display changing movement of a said element from one said position towards another and for retaining said element in said other position, and means for moving the row and the actuating means relative to each other to bring each element successively into cooperating relationship with the actuating means, said actuating means comprising trigger means movable in the path of travel of each said element, and at least one face of each said element having a co-operating surface for direct mechanical engagement with said trigger means for initiating said display changing movement of each element upon engagement of its said co-operating surface with said trigger means.

2. A display unit according to claim 1, including means for successively energizing said actuating means in synchronism with movement of respective said elements into cooperating relationship therewith.

3. A display unit according to claim 1, including means for preventing accidental display changing movement of a said element from one said position towards another whenever said actuating means is inoperative.

4. A display unit according to claim 1, including means for preventing display changing movement of a said element from one said position towards another whereby to override said actuating means and render the same inoperative.

5. A display unit according to claim 1, wherein said actuating means for moving a said element from one position towards another includes means sensitive to the orientation of an element presented to it whereby said actuating means combines the functions of actuation and resetting.

6. A display unit comprising an interconnected row of elements each having a pair of opposite faces of mutually distinctive character, each said element being mounted for independent pivotal display changing movement relative to the row between a pair of stable positions approximately 180 apart, in each of which positions one or other of the faces of each element defines a display array with the displayed faces of the other elements, actuating and indexing means for initiating and completing display changing movement of a said element from one said position towards the other and for retaining said element in said other position, and means for moving said row and said actuating means relative to eachother to bring each element successively into cooperating relationship with said actuating means, said actuating means comprising trigger means movable in the path of travel of each said element, and at least one face of said element having a cooperating surface for direct mechanical engagement with said trigger means for initiating said display chang ing movement of each element upon engagement of its said co-operating surface with said trigger means.

7. A display unit comprising a belt mounting a plurality of multi-faced elements arranged in rows and columns on said belt, each said element being mounted for independent pivotal display changing movement relative to said belt between a plurality of stable positions in each of which a respective distinctive face of said element defines a display array with the displayed faces of the other elements, a plurality of stationary actuating means for effecting a display changing movement of a said element from one said position towards another, indexing means for completing said display changing movement and retaining an element so moved in a said stable position, each actuating means corresponding to a row of said belt, and means for moving said belt relative to said actuating means to bring each element of each row successively into cooperating relationship with the actuating means associated with that row, said actuating means comprising trigger means movable in the path of travel of each said element, and at least one face of each said element having a co-operating surface for direct mechanical engagement with said trigger means for initiating said display changing movement of each element upon engagement of its said co-operating surface with said trigger means.

3. A display unit comprising a row of multi-faced elements each mounted for independent pivotal display changing movement relative to the row, guide means extending along said row for sliding cooperation with a face of each element whereby to define -a plurality of stable positions for each element, in each of which positions one or other of the faces of each element defines a display array with the displayed faces of the other elements, actuating means for initiating and completing display changing movement of a said element from one of said positions to another, and means for moving said row and said actuating means relative to each other to bring each element successively into cooperating relationship with said actuating means, said actuating means comprising trigger means movable in the path of travel of each said element, and at least one face of each said element having" a co-operating surface for direct mechanical engagement with said trigger means for initiating said display changing movement of each element upon engagement of its said co-operating surface with said trigger means.

9. A display unit according to claim 8, including a recess in said guide means for ensuring complete turning of an actuated element.

ll). A display unit comprising a row of elements, each having a pair of approximately fiat opposite faces of mutually distinctive character, each said element being mounted for independent pivotal display changing movement relative to the row between a pair of positions approximately 180 apart, in each of which'positions one or the other of the faces of each element defines a display array with the displayed faces of the other elements, triggering means for initiating rotation of a said element from one said position towards the other, means for moving said row and said triggering means relative to each other in the direction of extent of the row to bring the elements successively into co-operation relationship with the triggering means, said trigger means being movable in the path of travel of each said element, and at least one face of each said element having a co-operatin-g surface for direct mechanical engagement with said trigger means for initiating said display changing movement of each element upon engagement of its said co-operating surface with said trigger means, and indexing means associated with each element, said indexing means completing the approximately 180 rotation initiated by said actuating means and maintaining said element in its new position defining a display array with the displayed faces of the other elements.

11. A display unit comprising a row of elements each having a pair of flat opposite faces of mutually distinctive character, each said element being mounted for independent pivotal display changing movement relative to the row; guide means for engaging said faces of the elements along one side of the row to define for each element a pair of stable positions approximately 180 apart; means for moving said row and said guide means relative to each other in the direction of extent of the row; an actuating lug on each element projecting from one of said faces thereof towards said guide means; actuating means movable between an actuating position in the path of travel of said lug and a non-actuating position withdrawn from said path; said guide means having a recess positioned adjacent said actuating means to receive the leading edge of an element rotation of which has been initiated by said actuating means and to ensure completion of said rotation through 180 to reverse the face of such element slidingly engaging said guide means.

12. A display unit according to claim 11, including resilient means positioned to act on each said element in the vicinity of said recess to inhibit accidental rotation of said element into said recess when said actuating means is in non-actuating position.

13. A display unit according to claim 11, including a resetting lug on each element projecting from the face thereof opposite to that from which the actuating lug projects, said lugs being out of alignment with each other so as to define different paths of relative travel, the actuating position of said actuating means lying in the path of said actuating lug and the non-actuating position of said actuating means lying in the path of said resetting lug.

14. A display unit comprising (a) a row of elements each having a pair of opposite fiat faces of mutually distinctive character, each said element being mounted for independent pivotal display changing movement relative to the row,

(b) guide means for slidingly engaging faces of said elements along one side of said row to define a pair of stable positions approximately 180 apart for each element, in each of which positions one or other of the mutually distinctive faces of each element defines a display array with the displayed faces of the other elements, said guide means having a recess,

(c) means for moving the row and said guide means relative to each other in the direction of extent of the row,

(d) a pair of lugs each projecting from a respective face of each element, said lugs being out of alignment with each other and each element being provided with a pair of slots in :the body thereof, each slot in alignment with a respective lug, the slot corresponding to each l-ug being positioned in advance of said lug in the direction of relative travel of the row when the element is oriented with such lastmentioned lug projecting towards said guide means,

(e) and actuating means for cooperation with said lugs located adjacent the recess in said guide means,

(f) said actuating means being movable between two positions, in a first of which positions said actuating means lies in the path of travel of a first lug of each element approaching said actuating means oriented with said first lug projecting towards the guide means so that such element will be rotated by contact between said first lug and said actuating means, said rotation taking place in said recess with the actuating means temporarily occupying the slot in said element corresponding to said first lug, while in the second of which positions said actuating means lies in the path of travel of the second lug of each element approaching said actuating means oriented with said second lug projecting towards the guide means so that such last-mentioned element will be rotated by contact between said second lug and said actuating means, said rotation taking place in said recess with the actuating means temporarily occupying the slot in such element corresponding to said second lug.

15. A display unit according to claim 14, wherein each said element includes surfaces cooperating with said actuating means to prevent rotation in said recess of an element that approaches said actuating means with the lug projecting towards the guide means out of alignment with said actuating means.

16. A display unit comprising a row of multi-faced elements each mounted for independent display changing movement relative to the row between a plurality of stable positions in each of which a respective distinctive face of said element defines a display array with the displayed faces of the other elements, an actuating lug projecting from at least one face of each element, actuating means movable into an actuating position in alignment with said lug for initiating movement of a said element from one said position towards another, indexing means for completing said movement and for retaining said element in said other position, and means for moving the row and the actuating means relative to each other to bring each element successively into cooperating relationship with the actuating means.

17. A display unit comprising a row of multi-faced elements each mounted for independent display changing movement relative to the row between a plurality of stable positions in each of which a respective distinctive face of said element defines a display array with the displayed faces of the other elements, actuating lugs on each element projecting one from each face at different levels, actuating means movable from a non-actuating position to an actuating position aligned with said levels for initiating movement of a said element from one said position towards another, indexing means for completing said movement, and for retaining said element in said other position, and means for moving the row and the actuating means relative to each other to bring each element successively into cooperating relationship with the actuating means.

18. A display unit comprising a row of elements each having a pair of opposite faces of mutually distinctive character, each said element being mounted for independent pivotal display changing movement relative to the row between a pair of stable positions approximately apart, in each of which positions one or other of the faces of each element defines a display array with the displayed faces of the other elements, an actuating lug on each element projecting from one of said faces, actuating means movable from a non-actuating position to an actuating position aligned with each said lug for initiating movement of a said element from one said position towards the other, indexing means for completing said movement and for retaining said element in said other position, and means for moving said row and said actuating means relative to each other to bring each element successively into cooperating relationship with said actuating means when in the actuating position.

19. A display unit according to claim 18, including a resetting lug on each element projecting from the fz tce thereof opposite to that from which the actuating lug projects, said lugs being out of alignment with each other so as to define different paths of relative travel, the netu-ating position of said actuating means lying in the path of said actuating lug and the non-actuating position of said actuating means lying in the path of said resetting lug.

21 A display unit according to claim 11?, wherein said indexing means, associated with each element, for completing movement of said element from one position to another, includes use of ravity of the rotating element to help complete movement of said element once said movement is triggered.

EUGENE R. CAPOZIO, Primary Examiner.

JEROME SCHNALL, Examiner.

IOHN V i ILL, WILLIAM GRIEB, Assistant Examiners. 

1. DISPLAY UNIT COMPRISING A ROW OF MULTI-FACED ELEMENTS EACH MOUNTED FOR INDEPENDENT DISPLAY CHANGING MOVEMENT RELATIVE TO THE ROW BETWEEN A PLURALITY OF STABLE POSITIONS IN EACH OF WHICH A RESPECTIVE DISTINCTIVE FACE OF SAID ELEMENT DEFINES A DISPLAY ARRAY WITH THE DISPLAY FACES OF THE OTHER ELEMENTS, ACTUATING AND INDEXING MEANS FOR INITIATING AND COMPLETING DISPLAY CHANGING MOVEMENT OF A SAID ELEMENT FROM ONE SAID POSITION TOWARDS ANOTHER AND FOR RETAINING SAID ELEMENT IN SAID OTHER POSITION, AND MEANS FOR MOVING THE ROW AND THE ACTUATING MEANS RELATIVE TO EACH OTHER TO BRING EACH ELEMENT SUCCESSIVELY INTO COOPERATING RELATIONSHIP WITH THE ACTUATING MEANS, SAID ACTUATING MEANS COMPRISING TRIGGER MEANS MOVABLE IN THE PATH OF TRAVEL OF SAID ELEMENT, AND AT LEAST ONE SURFACE OF EACH SAID ELEMENT HAVING A CO-OPERATING SURFACE FOR DIRECT 